t/perf/p7527: add perf test for builtin FSMonitor

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/perf/p7527-builtin-fsmonitor.sh b/t/perf/p7527-builtin-fsmonitor.sh
new file mode 100755 (executable)
index 0000000..9338b9e
--- /dev/null
+++ b/t/perf/p7527-builtin-fsmonitor.sh
@@ -0,0 +1,257 @@
+#!/bin/sh
+
+test_description="Perf test for the builtin FSMonitor"
+
+. ./perf-lib.sh
+
+if ! test_have_prereq FSMONITOR_DAEMON
+then
+       skip_all="fsmonitor--daemon is not supported on this platform"
+       test_done
+fi
+
+test_lazy_prereq UNTRACKED_CACHE '
+       { git update-index --test-untracked-cache; ret=$?; } &&
+       test $ret -ne 1
+'
+
+# Lie to perf-lib and ask for a new empty repo and avoid
+# the complaints about GIT_PERF_REPO not being big enough
+# the perf hit when GIT_PERF_LARGE_REPO is copied into
+# the trash directory.
+#
+# NEEDSWORK: It would be nice if perf-lib had an option to
+# "borrow" an existing large repo (especially for gigantic
+# monorepos) and use it in-place.  For now, fake it here.
+#
+test_perf_fresh_repo
+
+
+# Use a generated synthetic monorepo.  If it doesn't exist, we will
+# generate it.  If it does exist, we will put it in a known state
+# before we start our timings.
+#
+PARAM_D=5
+PARAM_W=10
+PARAM_F=9
+
+PARAMS="$PARAM_D"."$PARAM_W"."$PARAM_F"
+
+BALLAST_BR=p0006-ballast
+export BALLAST_BR
+
+TMP_BR=tmp_br
+export TMP_BR
+
+REPO=../repos/gen-many-files-"$PARAMS".git
+export REPO
+
+if ! test -d $REPO
+then
+       (cd ../repos; ./many-files.sh -d $PARAM_D -w $PARAM_W -f $PARAM_F)
+fi
+
+
+enable_uc () {
+       git -C $REPO config core.untrackedcache true
+       git -C $REPO update-index --untracked-cache
+       git -C $REPO status >/dev/null 2>&1
+}
+
+disable_uc () {
+       git -C $REPO config core.untrackedcache false
+       git -C $REPO update-index --no-untracked-cache
+       git -C $REPO status >/dev/null 2>&1
+}
+
+start_fsm () {
+       git -C $REPO fsmonitor--daemon start
+       git -C $REPO fsmonitor--daemon status
+       git -C $REPO config core.fsmonitor true
+       git -C $REPO update-index --fsmonitor
+       git -C $REPO status >/dev/null 2>&1
+}
+
+stop_fsm () {
+       git -C $REPO config --unset core.fsmonitor
+       git -C $REPO update-index --no-fsmonitor
+       test_might_fail git -C $REPO fsmonitor--daemon stop 2>/dev/null
+       git -C $REPO status >/dev/null 2>&1
+}
+
+
+# Ensure that FSMonitor is turned off on the borrowed repo.
+#
+test_expect_success "Setup borrowed repo (fsm+uc)" "
+       stop_fsm &&
+       disable_uc
+"
+
+# Also ensure that it starts in a known state.
+#
+# Because we assume that $GIT_PERF_REPEAT_COUNT > 1, we are not going to time
+# the ballast checkout, since only the first invocation does any work and the
+# subsequent ones just print "already on branch" and quit, so the reported
+# time is not useful.
+#
+# Create a temp branch and do all work relative to it so that we don't
+# accidentially alter the real ballast branch.
+#
+test_expect_success "Setup borrowed repo (temp ballast branch)" "
+       test_might_fail git -C $REPO checkout $BALLAST_BR &&
+       test_might_fail git -C $REPO reset --hard &&
+       git -C $REPO clean -d -f &&
+       test_might_fail git -C $REPO branch -D $TMP_BR &&
+       git -C $REPO branch $TMP_BR $BALLAST_BR &&
+       git -C $REPO checkout $TMP_BR
+"
+
+
+echo Data >data.txt
+
+# NEEDSWORK: We assume that $GIT_PERF_REPEAT_COUNT > 1.  With
+# FSMonitor enabled, we can get a skewed view of status times, since
+# the index MAY (or may not) be updated after the first invocation
+# which will update the FSMonitor Token, so the subsequent invocations
+# may get a smaller response from the daemon.
+#
+do_status () {
+       msg=$1
+
+       test_perf "$msg" "
+               git -C $REPO status >/dev/null 2>&1
+       "
+}
+
+do_matrix () {
+       uc=$1
+       fsm=$2
+
+       t="[uc $uc][fsm $fsm]"
+       MATRIX_BR="$TMP_BR-$uc-$fsm"
+
+       test_expect_success "$t Setup matrix branch" "
+               git -C $REPO clean -d -f &&
+               git -C $REPO checkout $TMP_BR &&
+               test_might_fail git -C $REPO branch -D $MATRIX_BR &&
+               git -C $REPO branch $MATRIX_BR $TMP_BR &&
+               git -C $REPO checkout $MATRIX_BR
+       "
+
+       if test $uc = true
+       then
+               enable_uc
+       else
+               disable_uc
+       fi
+
+       if test $fsm = true
+       then
+               start_fsm
+       else
+               stop_fsm
+       fi
+
+       do_status "$t status after checkout"
+
+       # Modify many files in the matrix branch.
+       # Stage them.
+       # Commit them.
+       # Rollback.
+       #
+       test_expect_success "$t modify tracked files" "
+               find $REPO -name file1 -exec cp data.txt {} \\;
+       "
+
+       do_status "$t status after big change"
+
+       # Don't bother timing the "add" because _REPEAT_COUNT
+       # issue described above.
+       #
+       test_expect_success "$t add all" "
+               git -C $REPO add -A
+       "
+
+       do_status "$t status after add all"
+
+       test_expect_success "$t add dot" "
+               git -C $REPO add .
+       "
+
+       do_status "$t status after add dot"
+
+       test_expect_success "$t commit staged" "
+               git -C $REPO commit -a -m data
+       "
+
+       do_status "$t status after commit"
+
+       test_expect_success "$t reset HEAD~1 hard" "
+               git -C $REPO reset --hard HEAD~1 >/dev/null 2>&1
+       "
+
+       do_status "$t status after reset hard"
+
+       # Create some untracked files.
+       #
+       test_expect_success "$t create untracked files" "
+               cp -R $REPO/ballast/dir1 $REPO/ballast/xxx1
+       "
+
+       do_status "$t status after create untracked files"
+
+       # Remove the new untracked files.
+       #
+       test_expect_success "$t clean -df" "
+               git -C $REPO clean -d -f
+       "
+
+       do_status "$t status after clean"
+
+       if test $fsm = true
+       then
+               stop_fsm
+       fi
+}
+
+# Begin testing each case in the matrix that we care about.
+#
+uc_values="false"
+test_have_prereq UNTRACKED_CACHE && uc_values="false true"
+
+fsm_values="false true"
+
+for uc_val in $uc_values
+do
+       for fsm_val in $fsm_values
+       do
+               do_matrix $uc_val $fsm_val
+       done
+done
+
+cleanup () {
+       uc=$1
+       fsm=$2
+
+       MATRIX_BR="$TMP_BR-$uc-$fsm"
+
+       test_might_fail git -C $REPO branch -D $MATRIX_BR
+}
+
+
+# We're borrowing this repo.  We should leave it in a clean state.
+#
+test_expect_success "Cleanup temp and matrix branches" "
+       git -C $REPO clean -d -f &&
+       test_might_fail git -C $REPO checkout $BALLAST_BR &&
+       test_might_fail git -C $REPO branch -D $TMP_BR &&
+       for uc_val in $uc_values
+       do
+               for fsm_val in $fsm_values
+               do
+                       cleanup $uc_val $fsm_val
+               done
+       done
+"
+
+test_done